Drive and interrupter arrangement for rotary offset press

ABSTRACT

A perfecting offset printing press in which one blanket cylinder is directly driven to run the press, the plate cylinder cooperating with that blanket cylinder and the opposing blanket cylinder being mounted in throwoff eccentrics which are linked together and actuated for throwoff. One of the links is of variable length so that, by varying link length, the plate cylinder linked thereby can be skewingly adjusted. All cylinders run normally in bearing ring relationship, but the driven blanket cylinder is supported in shifting eccentrics permitting the driven blanket cylinder to be shifted from the other blanket cylinder while maintaining blanket cylinder-plate cylinder bearer ring relation. The gear driving the blanket cylinder has two engaged positions, one for each position of the blanket cylinder.

United States Patent [72] Inventor [21 Appl. No. [22] Filed [45] Patented [73] Assignee Leonard Immanuel Tafel La Grange, 111.

June 20, 1969 Jan. 11, 1972 Miehle-Goss-Dexter, Incorporated [54] DRIVE AND INTERRUPTER ARRANGEMENT FOR ROTARY OFFSET PRESS 3 Claims, 12 Drawing Figs.

References Cited UNITED STATES PATENTS Langston 101/247 UX Rowles 101/220 X Langetal. l0l/218X Robinson l01/247 plate cylinder bearer Tornberg lOl/247 ket cylinder has two Romaine et al 74/409 Buhrendorf.... 74/409 Royeret a1. 101/218 '1 i I/ L l z I l. A 2 j I, I "2 0 if x, 5

J I o i ii: :I: 5 D i e i o l/ /!//A '1' \i I, l\ y r I x- Wolff 101/180X Williams. 101/143 X FOREIGN PATENTS France Primary Examiner-J. Reed Fisher Attorney-Wolfe, Hubbard, Leydig, Voit & Osann, Ltd.

ABSTRACT: A perfecting offset printing press in which one blanket cylinder is directly driven to run the press, the plate cylinder cooperating with that blanket cylinder and the opposing blanket cylinder being mounted in throwoff eccentrics which are linked together and actuated for throwoff. One of the links is of variable length so that, by varying link length, the plate cylinder linked thereby can be skewingly adjusted. All cylinders run normally in bearing ring relationship, but the driven blanket cylinder is supported in shifting eccentrics permitting the driven blanket cylinder to be shifted from the other blanket cylinder while maintaining blanket cylinderring relation. The gear driving the blanengaged positions, one for each position of the blanket cylinder.

PATENTEU MN? i 1372 SHEET 2 [IF 6 alssa'so PATENYEB mu 1972 SHEET 3 BF 6 DRIVE AND INTERRUPTER ARRANGEMENT FOR ROTARY OFFSET PRESS DESCRIPTION OF THE INVENTION This invention relates generally to drive arrangements for rotary offset printing presses and more particularly concerns a drive, throwoff and adjusting mechanism for perfecting press units of that type.

Offset presses require, for registry purposes, accurate positioning of plate and blanket cylinders. Axial, radial, circumferential, and skewing adjustments are normally provided, and the press design problem is complicated by the need, in an offset press, to have quick, complete throwoff between plate and blanket cylinders and between perfecting blanket cylinders. When such adjustments and throwoffs are provided, it is a difficult problem to drive the plate and blanket cylinder since, despite shifting cylinder positions, the drive should be tight and as free of backlash as possible.

Accordingly, it is an object of the invention to provide a drive arrangement for a perfecting press which directly powers one of the blanket cylinders so that there is a minimum amount of backlash in the drive. A collateral object is to provide a drive arrangement of the above kind which also minimizes the number of gears involved and hence is economical to manufacture.

A further object is to provide an offset press throwoff arrangement for a drive of the above character that combines plate cylinder skew adjustment with the throwoff function in an economical and uncluttered mechanism.

Another object is to provide a drive as characterized above for an offset press which permits the blanket cylinders to run in either bearer ring relationship with each other, or slightly spaced to print heavier stock, without varying the running relationship between both blanket cylinders and their respective plate cylinders. A related object is to incorporate a mechanism in a drive of the above kind by which the alternate blanket cylinder spacing can be easily and simply set.

Other objects and advantages of the invention will become apparent upon reading the following detailed description and upon reference to the drawings, in which:

FIG. 1 is an elevation, partially in section, of a press unit embodying the invention shown in relation to adjacent units in a press;

FIG. 2 is an enlarged fragmentary elevation showing a portion of the press drive appearing in FIG. 1;

FIG. 3 is a fragmentary elevation again showing the drive portion of the press unit of FIG. 1 but with the gearbox wall not broken away;

FIG. 4 is a fragmentary slightly enlarged elevation of the unit printing couples appearing in FIG. 1 and is taken approximately along the line 44 in FIG. 5;

FIG. 5 is a fragmentary section taken through the drive side structure shown in FIGS. 1 and 4;

FIG. 6 is a fragmentary elevation similar to FIG. 4 but showing the opposite, operating side of the press unit and is taken along the line 66 appearing in FIG. 7;

FIG. 7 is a fragmentary section similar to FIG. 5 showing the operating side printing couple structure;

FIG. 8 is a fragmentary perspective, slightly enlarged, of a portion of the structure shown in FIG. 6;

FIG. 9 is a fragmentary section of the structure shown in FIG. 8;

FIG. 10 is a fragmentary section taken approximately along the line l0l0 in FIG. 6;

FIG. 11 is an enlarged elevation of a portion of the structure shown in FIG. 4; and

FIG. 12 is a fragmentary section taken approximately along the line 12l2 in FIG. 11.

While the invention will be described in connection with a preferred embodiment, it will be understood that I do not intend to limit the invention to that embodiment. On the contrary, I intend to cover all alternatives, modifications and equivalents as may be included within the spirit and scope of the invention.

Turning first to FIG. 1, there is shown a press unit 10 embodying the invention and forming a part of an offset press including similar units 11 and 12 at either side of the unit 10. The units 10-12 print in the perfecting, offset mode and act successively on a substantially horizontally travelling web 13.

The unit 10 includes a pair of blanket cylinders 15 and 16 and a pair of plate cylinders 17 and 18 geared together by helical spur gears 19 for rotation in bearings 20 supported on a pair of side frames 21 and 22 (see particularly FIGS. 5 and 7). The printing couples are driven by a drive shaft 25, journaled in gearbox walls 26 on the side frame 21, through a pair of bevel gears 27 and 28. The plate cylinders 17 and 18 are inked by inking arrangements 31 and 32, which are supplied with ink by upper and lower fountains 33 and 34, and are wetted by water arrangements 35.

In accordance with the invention, the driven bevel gear 27 is secured to the blanket cylinder 15, and the plate cylinder 17 and the blanket cylinder 16 are supported by throwoff eccentrics 36 and 37 mounted in the side frames 21, 22 and connected by links 38 and 39 for simultaneous actuation. The eccentrics 36 supporting the plate cylinder 17 are formed of inner and outer, relatively adjustable sections 41 and 42 so as to permit the plate cylinder 17 to be precisely positioned with respect to the blanket cylinder 16.

To operate the eccentrics 36, 37, an actuator 43 is anchored on the side frame 22 and connected through a bellcrank 44 to a pair of overcentering J-links 45 that are pivoted on the eccentrics 37 (see FIGS. 6 and 10). Contracting the actuator 43 throws off the plate cylinder 17 from the blanket cylinder 15, and the blanket cylinder 16 from the plate cylinder 18, the eccentrics 36 and 37 being coupled for simultaneous rotation by the links 38, 39. Extending the actuator 43 brings the cylinders back into printing relationship, and the overcentering .1- links 45 and a pair of stops 46 provide a fixed running position for the eccentrics 37. Similarly, stops 47 and 48 (FIGS. 4 and 6) provide solid printing positions for the eccentrics 36.

Preferably, the cylinders 15-18 all carry bearer rings 50 (see FIGS. 5 and 7) and, when in cooperating normal printing relationship, the bearer rings 50 run against one another. Thus, the J-links 45, the stops 46-48, and the bearer rings 50 provide solid positioning of the printing couples in their running relationships.

Pursuant to the invention, the link 39 is of variable length so that, by varying its length, the eccentric 36 at that end of the plate cylinder 17 can be rotated to provide skew adjustment of the cylinder 17. In the illustrated construction, the link 39 is formed of two sections 51 and 52 joined by a pivot 53 which is floatingly supported by a swinging arm 54. The arm 54 has a rounded head 55 mounted for universal movement in a nut 56 made up of a bearing 57 clamped between inner and outer sections 58 and 59 which are threaded together. The nut 56, in turn, is threaded in a split block 60 secured to the side frame 22 by three capscrews 61. A fourth screw 62 connects the split ends of the block 60 and, by tightening or loosening the screws 62, the nut 56 can be clamped firmly or released for turning. When released, the nut 56 is rotated by engaging a squared projection 63 on the inner nut section 58, and this rotation adjustably varies the position of the arm 54 so as to change the angle between the link sections 51, 52. Varying this angle changes the effective length of the link 59 and permits the cylinder 17 to be skewed even while the press is running. The other plate cylinder 18 also has a skewing eccentric 64 rotated by an am 65. The position of the arm 65 is controlled by a nut 66 in a split block 67, an arrangement corresponding to the nut 56 and the block 60.

Since the running position of the skewing eccentric 36 will vary, depending upon the skewing adjustment, the running stop 48 is a hard resilient stop defined by a bolt 68, slidably fitted in a support 69 on the side frame 22, urged toward the eccentric 36 by a plurality of alternately stacked Belleville washer springs 70. The springs 70 make the bolt 68 a hard stop against which the eccentric 36 is firmly positioned but also provide sufficient resilience to accommodate the skewing adjustment resulting from varying the length of the link 39.

As a feature of the invention, provision is made to establish a second running position for the blanket cylinder 15 which will space it slightly from the blanket cylinder 16 without disturbing the bearing ring running relation between the cylinders l and 17 and while maintaining proper drive to the blanket cylinder 15. This allows a heavier than normal stock to be printed without making extensive adjustments of the press unit 10.- To this end, the bearings 20 for the cylinder 15 are supported in eccentrics 72 mounted in the side frames 21, 22 (see FIGS. 11 and 12). The eccentrics 72 rotate between adjustable fixed stops 73, and each eccentric 72 is turned by crank elements 74 having offcenter pins 75 held closely between adjustable sides of forked extensions 76 formed on the eccentries 72. Turning flattened heads 77 on the crank elements 74 180 rotates the eccentrics 72 between the positions established by the stops 73. The eccentrics 72 swing the axis of the blanket cylinder 15 along a short radius arc 78 from one side to the other of a line 79 running between the centers of the cylinder 17 and the eccentrics 72. In one position of the blanket cylinder 15, the bearer rings 50 of that blanket cylinder engage the adjacent bearer rings 50 of both the plate cylinder 17 and the blanket cylinder 16. In the other position of the blanket cylinder 15, the bearer rings 50 of that blanket cylinder and of the plate cylinder 17 again come together, but the two blanket cylinders 15, 16 are spaced slightly to print on a heavier-that is, thicker web.

The drive bevel gear 28 is slidably splined on the drive shaft 25 so that the unit can be declutched and silenced from the remainder of the press. In the illustrated embodiment, the gear 28 is splined at 81 to a sleeve 82 that rotates with the shaft 25 and is interposed between the shaft and a bearing 83 supporting the shaft 25 in the wall 26 (see FIGS. 2 and 3). A ring 84 is coupled to the gear 28 through a thrust bearing 85, and a fork 86, pivoted at 87, is secured to the ring 84 by pins 88. An eccentric pin 91 on a shaft 92 engages a slot 93 in the end of the fork 86 so that, by rotating the shaft 92, the fork 86 can be pivoted to move the gear 28 from the solid-line, disengaged position shown in FIG. 2 into engagement with the driven bevel gear 27.

Since there are two positions for the blanket cylinder 15, described above in connection with FIGS. 11 and 12, there are also two positions for the driven bevel gear 27. To provide proper drive at all times, two engaged positions are established for the drive bevel gear 28. For that purpose, the shaft 92 has a mutually operated crank 95 having a head 96 that supports a pin 97 adapted to drop into either one of two holes 98 or 99 formed on the outer side of the gearbox wall 26 (see FIG. 3). Rotating the crank 95 so that the pin 97 drops into the hole 99 establishes proper meshing of the bevel gears 27, 28 when the blanket cylinder is in normal position, and rotating the crank 95 to the other hole 98 establishes proper meshing engagement of the bevel gears when the blanket cylinder is in its alternate position. Of course, rotating the crank 95 down to the clutch disengaged position illustrated in FIG. 3 completely separates the gears 27, 28 so as to declutch and silence the unit 10.

Those familiar with this art will appreciate that the drive discussed above provides a minimum number of gears, and hence a minimum amount of potential backlash, between the drive shaft and the printing couples. The drive shaft is directly connected to one of the blanket cylinders 15. Not only is potential backlash minimized, but the complexity and expense of the unit is reduced.

Complete throwofi is provided by throwing off the blanket cylinder which is not driven and the plate cylinder which engages the driven blanket cylinder. In the illustrated embodiment, this throwoff is combined with plate cylinder skew adjustment in an economical and uncluttered fashion.

The operating flexibility of the press unit 10 is greatly increased by the simple and convenient alternate positioning of the blanket cylinder 15 which allows a heavier, thicker stock to be printed without altering the many fine adjustments required for proper operation of an offset press. In their running or printing positions, the unit cylinders 15-18 are all locked solidly against stops and are in bearer ring engaging relationship so that the press unit is exceptionally smooth running.

I claim as my invention:

1. In an offset press having a pair of blanket cylinders and a pair of plate cylinders geared together for rotation in bearings supported on a pair of side frames, the combination comprising: a drive shaft on one of said side frames; a pair of meshed gears, attached respectively to the drive shaft and to a first one of said blanket cylinders, coupling said drive shaft directly with said first blanket cylinder; eccentrics rotatably mounted in said side frames for supporting the bearings of the plate cylinder cooperating with said first blanket cylinder and the bearings of the second blanket cylinder; links at each side frame coupling said eccentrics for simultaneous rotation, one of said links being formed of two sections joined by a pivot and having a variable effective length so that, by varying said length, one eccentric supporting one end of said plate cylinder is rotated to provide skew adjustment of that cylinder; a swinging arm pivotably attached to one of said frames for supporting said pivot; means for adj ustably varying the position of said arm so as to vary the angle of said sections about said pivot and thus change the effective length of the variable-length link; an actuator mounted on one of said side frames for rotating said eccentrics so as to simultaneously effect a separation between said plate cylinders and their respective blanket cylinders; and an actuator link connecting said actuator to the eccentrics supporting the second blanket cylinder.

2. In an offset press having a pair of blanket cylinders and a pair of plate cylinders geared together for rotation in bearings supported on a pair of side frames, the combination comprising, bearer rings disposed at opposite ends of each of said cylinders so that each blanket cylinder runs in bearer ring engagement with a respective one of said plate cylinders and the two blanket cylinders run in bearer n'ng engagement with each other, a drive shaft on one of said side frames, a pair of gears coupling said drive shaft with one of said blanket cylinders, one of said gears being movable out of engagement with the other gear of the pair so as to declutch the cylinders from the drive shaft, eccentrics rotatably mounted in said side frames for supporting the bearings of said one blanket cylinder, means for rotating said eccentrics so as to shift said one blanket cylinder out of bearer ring engagement with the other blanket cylinder and back into bearer ring engagement with its cooperating plate cylinder thus slightly spacing said blanket cylinders, and means for shifting said movable gear between a position out of engagement with said other gear to either one of two driving positions wherein the gears engage whether the shiftable blanket cylinder is in one position or the other.

3. The combination of claim 2 including throwoff eccentrics rotatably mounted in said side frames for supporting the bearings of the plate cylinder cooperating with said one blanket cylinder and the bearings of the other one of said blanket cylinders, links at each side frame coupling said eccentrics for simultaneous rotation, and an actuator mounted on one of said side frames for rotating said eccentrics so as to simultaneously throw off said plate cylinders from their respective bianket cylinders. 

1. In an offset press having a pair of blanket cylinders and a pair of plate cylinders geared together for rotation in bearings supported on a pair of side frames, the combination comprising: a drive shaft on one of said side frames; a pair of meshed gears, attached respectively to the drive shaft and to a first one of said blanket cylinders, coupling said drive shaft directly with said first blanket cylinder; eccentrics rotatably mounted in said side frames for supporting the bearings of the plate cylinder cooperating with said first blanket cylinder and the bearings of the second blanket cylinder; links at each side frame coupling said eccentrics for simultaneous rotation, one of said links being formed of two sections joined by a pivot and having a variable effective length so that, by varying said length, one eccentric supporting one end of said plate cylinder is rotated to provide skew adjustment of that cylinder; a swinging arm pivotably attached to one of said frames for supporting said pivot; means for adjustably varying the position of said arm so as to vary the angle of said sections about said pivot and thus change the effective length of the variable-length link; an actuator mounted on one of said side frames for rotating said eccentrics so as to simultaneously effect a separation betweEn said plate cylinders and their respective blanket cylinders; and an actuator link connecting said actuator to the eccentrics supporting the second blanket cylinder.
 2. In an offset press having a pair of blanket cylinders and a pair of plate cylinders geared together for rotation in bearings supported on a pair of side frames, the combination comprising, bearer rings disposed at opposite ends of each of said cylinders so that each blanket cylinder runs in bearer ring engagement with a respective one of said plate cylinders and the two blanket cylinders run in bearer ring engagement with each other, a drive shaft on one of said side frames, a pair of gears coupling said drive shaft with one of said blanket cylinders, one of said gears being movable out of engagement with the other gear of the pair so as to declutch the cylinders from the drive shaft, eccentrics rotatably mounted in said side frames for supporting the bearings of said one blanket cylinder, means for rotating said eccentrics so as to shift said one blanket cylinder out of bearer ring engagement with the other blanket cylinder and back into bearer ring engagement with its cooperating plate cylinder thus slightly spacing said blanket cylinders, and means for shifting said movable gear between a position out of engagement with said other gear to either one of two driving positions wherein the gears engage whether the shiftable blanket cylinder is in one position or the other.
 3. The combination of claim 2 including throwoff eccentrics rotatably mounted in said side frames for supporting the bearings of the plate cylinder cooperating with said one blanket cylinder and the bearings of the other one of said blanket cylinders, links at each side frame coupling said eccentrics for simultaneous rotation, and an actuator mounted on one of said side frames for rotating said eccentrics so as to simultaneously throw off said plate cylinders from their respective blanket cylinders. 